Lab report Example | Topics and Well Written Essays - 750 words

Lab Report Example Other human activities like clearing of land, deforestation, and desertification that abet temperature rise due to reduction in carbon dioxide sinks. Many scientists and environmental agencies have been actively informing the public and publishing scientific articles about the global warming and its adverse effects. They have strongly recommended governments and individual citizens to be actively involved in the mitigation and preparation for the effects of global warming. On the other hand, a group of people have also been actively rebutting the claims that global warming is here. This is called the â€Å"global warming debate.† What then are scientific evidences on which the claims â€Å"for† and â€Å"against† global warming are based? THE CASE FOR GLOBAL WARMING The increase in the earth’s surface temperature is blamed on human activities. From 1908 to 2008, the temperature of the earth’s surface has increased within the range of 1.2-1.4 ° C; the warmest years since 1850 occurred after 1998 (US Environmental Protection Agency). Greenhouse gases are naturally found on the earth’s atmosphere but their levels have significantly increased by 25% since massive industrialization which began more than 100 years ago (Energy Information Agency). Burning of fossil fuels by the energy and transportation sector accounted for 75% of greenhouse gas emissions, notably carbon dioxide. More intensive agriculture to feed increased population has increased methane and nitrous oxides concentration further. As a nation’s economy flourishes, so does its need for energy (US Environmental Protection Agency). Land surface temperatures are increasing faster than sea surface temperatures, while average temperatures are increasing faster with time (Intergovernmental Panel on Climate Change). Data show that the warmest years in the last century are: 1998, 2003, 2004, 2005, 2006, 2000, 2001, 1990, 1997, 1995 and 1999. Temperature increa se by 3 - 5 °F increases the risk of extinction of one-third of plant and animal species (Intergovernmental Panel on Climate Change). The rate in global sea level rise was ten times higher than the last 3000 years. This sea level rise is proportional to the temperature increase (Rahmstorf, 2006). Changes in climatic conditions due to global warming are well-documented and are projected to increase. These include precipitation (Wentz, Ricciardulli and Mears), further sea level rise (Meehl, Washington and collins), and thawing of ice sheets in Greenland and the Antarctic (Alley, Clark and Huybrechts). The widespread retreat and melting of glaciers (as shown in the CBS video) are attributed to global warming. In just forty-two years (1961-2003), the Antarctic and Greenland ice sheets have rapidly melted. The impacts of climate change are now being felt (summarized in Nurse). In the arctic and sub-arctic regions, imaging technologies show that glacial lakes have increased in number an d size. Warming of water bodies increase the runoff and earlier discharge of snow-fed rivers, and changed the water quality. Seasons have also shifted; notably spring events are earlier (i.e. bird migration). In agriculture and forestry, crop yields are affected due to higher night temperatures (Peng, Huang and Sheehy). Pests’ infestation is also expected to rise with increased temperatures reinforcing the need for more detailed monitoring (Logan, Regniere and Powell). Further evidences that global warming is here